The use of mobile devices and the resulting mobile traffic continues growing at a very fast pace and the trend shows no signs of stopping. To meet the mobile traffic growth and improve the end user experience, mechanisms are desired to improve network efficiency, system capacity, and end user experience by cost effectively leveraging radio network technologies. The routing of network traffic to a Wi-Fi radio and to a cellular radio, for example, can affect the user experience. For example, if the network traffic is routed to a network that is not appropriate for that network traffic, it can result in loss of the communication (e.g., dropped calls), poor services, and other negative impacts to the user experience.
To guarantee quality of service (QoS), a feasible cell selection scheme can enable small cells to associate with a base station (BS) that possesses the best channel and network conditions. In high-speed downlink packet access (HSDPA), fast cell selection (FCS) allows small cells to maintain an active set which contains the candidate BSs, and the small cell selects the serving BS (SBS) with the strongest pilot signal in the active set. The idea of FCS can be further applied into OFDMA networks for the LTE-A standard to facilitate the SBS selection in heterogeneous networks. To ensure customer satisfaction, network providers aim to deliver a high quality service at any location, and to facilitate reliable and efficient mobile communications. Consumers can access a growing number of networks using a mobile device and still receive QoS by reducing handover time delay and communication overheads in the network.
Nevertheless, the use of small cells can increase power consumption of a network. Over the past few decades there has been an increased focus on green technology and reducing energy consumption to benefit the environment. Reducing energy consumption can also have a positive economic effect as cost is reduced.